Petra Helena Grütter (née Müller) was born on 27 July 1935 in Botrivier in the Overberg. Müller matriculated in 1951 in Swellendam and graduated at the University of Stellenbosch.
After receiving her BA degree, she worked as a journalist for Die Burger and later as story editor for Sarie. In the 1980’s she was editor at Tafelberg Publishers. Since 1989 Petra Müller has been writing full time, but still does freelance work for publishers.
She is a renowned poet and short story writer. Her first book of poetry, Obool, was published in 1977. In 2005 she was awarded the Hertzog prize for poetry for Die aandag van jou oë (Eng. the attention of your eyes).